"Quantum dots (QDs) are often considered as promising candidates for applications in a variety of novel devices with spin-enabling functionality, e.g. in spin light-emitting devices, for spin filtering, as well as in quantum information technology," the authors write.

The researchers showed that independent (free) carriers are more efficient than electron-hole pairs (excitons) for creating specific spin orientations in InAs quantum dots.

This finding is relevant for future quantum communication and quantum information storage because it points out that separate carrier injection can be advantageous for next-generation spintronic devices based on QD spins.